The First IMS AG Face2Face Event is Here
September 25, 2007
It’s about time this happened. We’ve been working for several months now in the IMTC IMS AG for this moment – the first face-to-face interoperability event of our group.
Why is this important?
Up until today, no real IMS testing was done for the client side in any methodical way. Sure, the IMS Forum is doing PlugFest events and the GSMA is also doing some basic interoperability testing for their specification. Nevertheless, there’s no real place where handset vendors and middleware/software providers for handsets can gather around on a regular basis and deal with interoperability. The IMS AG is just that place.
What do we focus on?
We currently deal with Video Share as an IMS service that we are testing, focusing on the client itself. Not what is required on the network side and how billing is done but rather how two mobile clients can call each other, negotiate the parameters they will use for the call and share a video session between each other. We will be moving on to additional client-side service aspects as they develop – we started with Video Share simply because it seems like one of the services of IMS that will be deployed first – I believe AT&T is the first of many operators that will focus on Video Share in the next couple of months.
What do we do?
We talk once a week or two, depending on availability. Companies in the group join a conference call to discuss matters at hand. In these calls we discuss a wide range of topics:
- Drafting out our test case document
- Establishing and discussing liaison connections with other organizations (GSMA, IMS Forum, OMTP and others)
- Scheduling interoperability events
Our goal?
To make sure that once operators decide to deploy services such as Video Share, they will be able to choose any phone vendor they want and be confident of the level of interoperability provided. This means that operators would rather take handsets from vendors who are actually test interoperability in the IMTC IMS AG.
October interoperability event
Our first event is scheduled for October 10-12 this year. RADVISION, my company, is hosting this event along with the 3G-324M AG, which will do their own interoperability testing there.
We are planning to convene after the event and publish the first official test cases document for Video Share from the IMTC. As usual, I am sure we will have some comments to the 3GPP and the GSMA that might require some clarifications or changes to the specifications – that happens when an activity group in the IMTC starts doing interoperability and places a specification under its magnifying glass…
If you do develop communication products, you must know that interoperability is important. What do you do to close this gap of interoperability in your products?
Technorati Tags: IMTC, IMS, IMS Client, Video Share, GSMA, IMS Forum, OMTP, 3GPP, Interoperability, 3G-324M, Tsahi Levent-Levi
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Would you like to meet F2F in the Holy land?
September 25, 2007
By Oren Libis
On October 8 -12, the company that I work in, RADVISION, is going to host the next IMTC 3G-324M AG F2F event in Tel-Aviv, Israel, and I am in charge of the organization of the event. This is not the first time RADVISION organizes such an event. The first event took place on February 2006 and yet the upcoming event is exciting just as much and even more.
I participated in many IMTC F2F events in the past 5 years and I traveled to many countries but hosting an event in your home country is completely different feeling. The fact that many people from different companies, countries and cultures get together in one place and work together is something wonderful but when it happens in your home field it is even more wonderful.
I very much enjoy hosting these people which I consider friends, telling them about my country, showing them the holy places, elaborating on the local customs and introducing them to the local food. This is amazing time and again to see their reaction to that. This makes me very proud in my country and very enthusiastic to show more and more.
In the previous event we visited in the holiest place in Israel – Jerusalem. This time we are going to visit in Caesarea. Our goal is to improve the hosting from event to event and so we have some more surprises this time that I am not going to tell otherwise I will spoil the surprise.
And yes, we are even going to work here between visits and test 3G-324M devices. But, I am sure that the special atmosphere and the activities around the event will ease the pressure of the work and make it more pleasant.
I hope that more and more people even from companies outside IMTC read this post and decide to join the event. I hope to see you F2F next month in the Holy Land…
Technorati Tags: 3G-324M, F2F, IMTC, RADVISION, Oren Libis, Interoperability
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Will 3G-324M MONA be here this Christmas?
September 9, 2007
By Oren Libis
MONA (H.324 Annex K), the chosen call setup time reduction technique, was approved by the ITU-T and 3GPP over a year ago. How come we don’t see it in the market yet? It is mainly an issue of standardization and timing.
From past experience in 3G market, it takes about 6 – 12 months since a company has a prototype till the first model gets into the market. This happened in other standards and it has happened in 3G-324M time and again – WNSRP and channel negotiation conflicts are examples of this.
During this time many 3G-324M terminal vendors are working vigorously and intensively on their MONA implementations. Some of the implementations are more mature than others but all in all there is much more work to be done.
Implementing is not enough – you now need to test it. Most of the testing sessions are conducted in the 3G-324M Activity Group Face2Face events of IMTC. In these events many vendors perform interoperability testing against others but this is not that easy for new standards. H.324 Annex K is quite a complicated technique, which changed significantly the way 3G-324M call setup was done till now, so one can expect many interoperability clashes in the beginning of the testing – we’ve seen those in the last three events already. Obviously, the prototypes also need to maintain a very high level of interoperability with legacy terminals which makes it even harder. However, the interoperability level gets improved from event to event and the implementations mature as time passes. The upcoming Face2Face event in Tel-Aviv, Israel on October 8-12 will definitely show high level of interoperability as this is the 4th event that MONA is being tested.
Taking into account all of the above, I would expect to see MONA enabled models out in the market during the second half of 2008. Some initial models might actually hit the market prior to that, and maybe, just maybe, there will be a vendor or two that make it to Christmas this year.
Technorati Tags: 3G-324M, IMTC, Interoperability, ITU, Oren Libis
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Beginner’s Guide to 3G-324M MONA
August 15, 2007
By Oren Libis
MONA is a call setup time reduction technique used in 3G-324M. In the past several weeks I have noticed that a lot of handset developers and operators out there – not members of the IMTC, are a bit confused at what MONA is and how it really works.
The 3G-324M Activity Group in the IMTC is working hard in the past year on MONA. We’re doing interoperability testing whenever we can and we are going to meet again during October 8-12 for a face-to-face interoperability event with MONA as one of the main items.
What is MONA?
MONA is a call setup time reduction specification for 3G-324M. It is a set of 3 different techniques: MPC, SPC and ACP. I won’t go into the technical aspects of each, but it is important to understand the following points:
- Each of these techniques alone can reduce call setup time to below 1 second.
- Each of these techniques has its advantages and disadvantages – this is why MONA specifies three different techniques and not only one.
MONA Classes
3G-324M MONA specifies in addition to these 3 techniques, 3 different classes. 3G-324M products need to support only one of these classes. Each class indicates which of the 3 techniques (MPC, SPC and ACP) need to be implemented:
- Class 1, which requires MPC, SPC and ACP
- Class 2, which requires MPC and ACP
- Class 3, which requires SPC and ACP
The different MONA classes are interoperable with each other. For example, if two handsets support MONA, one supporting class 1 and the other supporting class 2, the call that will be established will either end up using MPC or ACP; if one supports class 2 and the other supports class 3, the call will simply use ACP.
What does is mean to you?
- If you are a developer, you should choose to develop the class that makes the most sense to you in terms of resources, footprint, memory and time to market.
- If you are a mobile operator, you should not force vendors to support a specific class – let your vendors choose their own class – in the end result, you will still get below 1 second of call setup time and you will be giving the vendors some flexibility.
Technorati Tags: 3G-324M, MONA, IMTC, Interoperability, Oren Libis
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Interoperability in the Real World, Part 2
August 10, 2007
By Oren Libis
Last time, I tried to explain my view on the GCF test cases. As these are test cases that you need to pass before deploying your product (by going to GCF test labs), no matter how farfetched they are, you need to handle them. But there are another important interoperability issues that the GCF doesn’t handle. These are the real deployments out there today.
There are a large and growing number of 3G handsets out there and they are coming from several handset vendors. Each one has its own behavior and quirks. You’d be amazed how much effort it takes when you develop a 3G-324M stack to handle all of these quirks and how much you need to invest on the codec level and application level to get things done right.
Difference in behavior
This difference in behavior happens due to the complexity and richness of 3G-324M. Granted – it does only a video call, in a straightforward enough scenario, but the amount of options that this single scenario has is almost unlimited:
- It supports multiple types of codecs each with its own set of configurable parameters
- There are H.245 messages flowing
- Media quality needs to be handled differently by the various media systems out there
- Different developers have implemented 3G-324M, each one understanding the standard in his own way
Server side equipment
There are also servers on the network. These most of the time are using circuit switched networks in front of the handsets, where they are running 3G-324M, but they are also using IP based standards such as H.323 and SIP on the network side, when interacting with media servers for example. They have a different kind of behavior than handsets and they have a different decision making processes designed into them, bringing in more interoperability issues to bear.
What do you do?
The most important suggestion I can give developers of 3G-324M products is to do the GCF test cases that they must in order to get validated, but to focus and invest a lot on the handsets and servers interoperability. Try to get your hands on as much information as possible during your development regarding the differences in behavior of the handsets and servers and make sure you test against as many handsets as possible before you try to deploy your product through an operator.
Technorati Tags: 3G-324M, WCDMA, Interoperability, GCF, Oren Libis
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Interoperability in the Real World
July 23, 2007
By Oren Libis
Managing interoperability for 3G-324M is not easy if you are a handset developer. There’s a lot to be done and some of it doesn’t always make sense.
What happens when a handset manufacturer finish developing and testing his 3G handset and wants to go sell it through an operator?
This seems like a straightforward enough process: you take the handset, you make sure you test it properly in your labs with a professional QA team and you’re done. That may be the case for things long supported by 3G handsets, such as audio calls over GSM or sending SMS messages, but for 3G-324M this is usually a bit more complex.
3G-324M testing has several different test phases: there are the IMTC, which does interoperability events – and publishes test cases, you have the GCF test labs, which validate handsets using a subset of the IMTC test cases, and then you have handsets and servers that are already deployed.
I have been working for a long time now with handset manufacturers and I have come to the conclusion that sometimes the focus is on the wrong kind of tests.
It might take a bit of time, so let me start by focusing on the GCF.
Take the GCF selected test cases for example. Since most of them are important when you validate your handset – they are all mandatory. But from analyzing them closely you can easily split them up into 3 distinct groups:
- Important test cases
- “Nice to have” test cases
- Unnecessary test cases
I’ll give an example of each. By the way, as the GCF test cases are simply references to the IMTC, you can find all of these test cases here, separated into two distinct documents: interoperability and compliance.
Important test case
An example of an important test case is test case 54. It deals with master slave conflicts – a situation that is common when you have a call between two handsets from different vendors. A few years ago, a lot of handsets on the market and those developed by IMTC companies were unable to pass this test case. As this one deals with a plausible and common scenario, it is important to test it.
“Nice to have” test case
A “Nice to have” test case is test case 47. It checks to see if a handset is capable of accepting a change in media transmission rate because the other terminal/server requested him to do so. I have never quite seen this kind of a scenario happen in real life (it might, I just never saw it). You can take my word for it that this procedure is not that necessary and effective when video is presented on a small screen like the one used in 3G handsets. So this is a “nice to have” test case in my view – it’s a good enough feature, but the problem it comes to fix is just not there most of the time.
Unnecessary test case
An unnecessary test case is test case 45 (and 45u). In this test case, you need to respond to a RequestMultiplexEntry message – either by acknowledging it and sending the entry’s information or rejecting it. If someone is sending it to you, it means that he is already in a lot of trouble, as he didn’t remember what you told him (there are only 16 entries, so this must make him a senile). Let’s assume you reject it – this makes him unable to do a thing about it but drop the call. So we have a test case where the one you are working against is faulty/senile – you choose, and you can decide you don’t support this feature, hence causing a disconnection (and you are still validated by the GCF!). I have never seen a real handset acting in this kind of a way when the terminal he was working against was doing his part of the job. This means that developers need to handle this test case (and a few others similar to it) although their handsets will never actually be in this scenario.
Distinguishing between the different test cases is not easy and requires some knowledge in 3G-324M and in what different products, both handsets and server, are doing. At the IMTC’s 3G-324M Activity Group each company gets to work against a large variety of companies and products with the actual QA and development teams of these companies. This provides important information that can assist any handset vendor to pass his interoperability tests once he gets to that point.
Technorati Tags: 3G-324M, WCDMA, Interoperability, IMTC, GCF, Oren Libis
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Hosting an Interoperability Event
July 15, 2007
By Oren Libis
It is now final. My company will be hosting the next face-to-face interoperability event for the 3G-324M activity group on October 8-12, 2007. It has been a bit over a year since we hosted our last event and it seems like I am getting the hang of it.
As we are planning our next event, there is this shopping list of issues that we will be taking into consideration:
- Location
Need to find a big enough place to accommodate the group. A table for each company, with some space between them. - 3G coverage
We have to make sure that there is good 3G coverage in the location of the event and that it can hold a capacity of 10 or more video calls simultaneously. - ISDN lines
BRI and PRI. There are those that don’t have direct access to the 3G network, or those companies that would like to test their gateways, so we need to provide ISDN access as well. - Connectivity of 3G and ISDN
Now that there are two separate networks (3G and ISDN), we must check that you can call from one to the other and vice versa. - Wireless LAN
Everyone wants to use the internet during this week. Might as well provide good access to it. - Lunch
The army walks on his stomach and engineers can’t think without sugar. We have to make arrangements for lunch each day – in different restaurants, with English menus. - Social event
We’re hosting the event, so we need to give people some good time. Last year it was Jerusalem – this time it is still open. Any suggestions?
There are additional issues such as banners for the event, visa invitations, and restaurants for the evenings…
This event is definitely going to be around MONA call setup time, H.264 video codec and AMR-WB speech codec again, but I have a pretty good feeling that these should go even better than the last time for our group. I can’t wait to meet all of the guys here in Israel!
Technorati Tags: 3G-324M, Interoperability, MONA, RADVISION, Oren Libis
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3G-324M – From Connectivity to Services
June 26, 2007
By Oren Libis
Today, 3G-324M is used for video telephony and it is deployed in Europe and Asia, and many many handsets. China is now joining the bandwagon as well, with their TD-SCDMA network.
At the IMTC, we have been covering the adoption of 3G-324M over the last several years, especially from the point of view of the handset. This includes interoperability testing between two points, each running 3G-324M. During that time, we focused on making sure that channels are opened properly, and that video codecs are negotiated reasonably. From there, we moved on to handling call setup time. Along the way, other technical issues were dealt with and solved.
Today, I feel confident that the technical issues of video calls between two handsets are solved. The level of interoperability we have achieved within our group is high. I am also quite impressed by the level of interoperability that the newest addition to the standard – H.324 Annex K (also known is MONA) enjoys. I had my doubts, but during the last SuperOp! event on April, I was able to interoperate quite well with several vendors – no small achievement for a new specification that several companies are implementing independently.
And this led me to think about what’s next in store for our Activity Group. 3G-324M is relatively limited. You can use it to open multiple multimedia channels between two points, and this is mainly used to execute video telephony calls. You can try adding text, adding more codecs or trying to increase the bandwidth, but I believe the next challenge for the 3G-324M AG will be services.
As 3G-324M is used by operators to offer interactive video services to customers, our primary concern should be making sure that 3G-324M is as flexible as possible for services. We already have basic calls up and running well. But there are other technical aspects that didn’t get as much attention as they needed. Deploying a video ring-back tone service, for example, is a technical challenge due to the way 3G-324M is defined. This is an issue that makes the deployment of such a service so expensive to operators. From my conversations with service providers, I believe that there are a lot more services that subscribers would like, but we don’t handle well enough. So we have our work cut out for us.
If you are an operator or if you are in the business of developing services for operators, I suggest you join the IMTC 3G-324M Activity Group. The time has come to make 3G-324M services a reality.
Technorati Tags: 3G-324M, ITU, MONA, Oren Libis, TD-SCDMA, WCDMA
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TD-SCDMA Video Telephony and Interoperability
June 15, 2007
By Oren Libis
In the IMTC 3G-324M Activity Group we handle interoperability for video telephony. The companies participating in this group focus on WCDMA, though other networks can be easily supported as well.
Recently, we have noticed that China is working more quickly on building its TD-SCDMA network building – most probably because of the Olympic Games planned for next year. TD-SCDMA also enables use of 3G-324M for video telephony like WCDMA – you get a 64kbps circuit switched connection in both directions of your call and you use it to transmit H.324 bit streams.
If we try to predict what’s in store for the TD-SCDMA industry, it seems like the IMTC can offer a lot to China in terms of experience with 3G-324M interoperability. We know the companies, the technology, and the facilities that test video telephony. We handled standardization when it was required and have seen more and more products conform to the 3G-324M standard and improve interoperability.
As TD-SCDMA embarks on its first steps as a live network, I am sure that vendors will face the same interoperability problems that we faced in the beginning of WCDMA. But this time, there are lessons to be learnt from our experience developing and deploying WCDMA handsets and services. My feeling is that interoperability between TD-SCDMA and WCDMA is also important.
I would like to invite all TD-SCDMA vendors out there to join us in the IMTC. Benefit from the vast experience we have accumulated and be part of our efforts to promote the use of 3G-324M in mobile handsets. There’s a lot of work to be done. We’re here to help.
Technorati Tags: 3G-324M, Oren Libis, TD-SCDMA, WCDMA
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I’m very excited to be the first to welcome you to the IMTC Blog! As a popular saying goes, it is hard to teach old dogs the new tricks. IMTC is 14 years old, so in the terms of age technology, it is quite an honorable age. A lot of young engineers today might even question the sheer existence of the standards IMTC was all about. However, IMTC as an organization is evolving, and we do “learn new tricks” and reinvent ourselves. We moved from H.320 to H.323, then to Packet Switched, SIP and 3G Mobile Video. We continue evolving further to IMS and Content Delivery.
IMTC managed to build an incredibly valuable collection of standardization-related documents for such technologies like JPEG (we call this collection a Historical Archive). While organization evolved, the core things IMTC is all about stayed the same – standards, interoperability and expertise.
IMTC always advocated multimedia communications technologies based on open standards. The focus of the IMTC work is Real Life Interoperability. With numerous Interoperability testing events, including the flagship annual SuperOp! event, IMTC is well known in the industry as leading authority on interoperability testing. And with IMTC Forums, we always bring together world experts in multimedia communications and standards development. And this combination of expertise and leadership makes me believe in exciting future prospects of IMTC.
I do like science fiction a lot. While driving today to work, I was thinking about predictions made in the books about the ways we will communicate. And one thing did strike me is that almost everything which was dreamed of, except may be “Beam me up, Scotty”, is the reality today. We can see and hear each other any time any place, we always know our exact location, our cars can park themselves…if you are a science fiction writer, what kind of communication technologies will you envision? Well, I’m sure, whatever we will come up with, IMTC will be around to make sure it is interoperable and to promote it.
And while the new technologies are being invented, IMTC is continuing on its current way, and inviting you to join in. Next week at VON in San Jose, IMTC puts together a panel of experts who will discuss the role of standards in the today’s communications world. More info is available here: http://www.von.com/schedule_gcs31168946047.html
Then in April, IMTC members will get together for annual SuperOp! 2007 event ( April 23-27, in Jesi, Italy), to test all the latest developments in SIP, IMS, 3G-324M, Packet Switched and other technologies. And of course we have more events planned throughout 2007 and beyond. Bottom line is very simple – if your company is not a member of IMTC yet, make it high priority to join IMTC and help shaping the future of multimedia communications!
Have a great interoperable communications day!
